Due to their known advantages such as high energy efficiency, small size and long lifetime, LEDs are increasingly used today in lighting and signaling applications. Retrofit LED lamps are replacing other technologies such as incandescent lamps or fluorescent lamps.
Such LED lamps are designed safe for the user, i.e. any life electrical parts, such as the electrical circuit comprising the LED element, are covered, so that a direct contact with the operating voltage, which could result in an electric shock, is prevented in normal operation and handling of the LED lamp. However, problems may arise if the LED lamp is damaged.
WO 2011/027278 A1 describes an LED lamp with at least one LED in a housing. An isolation monitoring device determines a defect of the housing and in this case disconnects the LED from power. The isolation monitoring device may comprise a detection circuit integrated with the housing, or a pressure sensor to detect a defect. Switches may be provided for all-pole disconnection of the LED, or to short-circuit a fuse for permanently disconnecting the LED from power.